Expected car use reduction in response to structural travel demand management measures

Selecting the appropriate travel demand management (TDM) measures aiming to reduce the environmental problems associated with private transportation demands a thorough understanding of the behavioral consequences of different measures. In this scenario based study, the expected car use reduction in response to one push measure (i.e. raised tax on fossil fuel), one pull measure (i.e. improved public transport), and a combination of the two measures were analyzed. The aim was to compare the expected car use reduction in response to the different TDM measures, the car use reduction strategies used to achieve this reduction, and factors important for the expected car use reduction (i.e. background factors, internal motivational factors (general intention and personal norm), and perceived personal impact of the measure). In a two step between-subject design, a sample of car users first answered a pre-questionnaire and subsequently three groups of car users (N = 274) each evaluated one of the TDM measures. Results demonstrated that the combined measure led to larger expected car use reduction compared to the measures evaluated individually and the reduction was mainly expected to be made by means of trip chaining and changing travel mode. Moreover, internal motivational factors, such as personal norm or general intention, and the perceived impact of the measure, were found to be important for the expected car use reduction in response to the TDM measures.